Revert of Revert of Drive: Let DriveUploader use batch request API.

chrome/browser/chromeos/drive/job_queue.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/drive/job_queue.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
@@ skipping 23 matching lines @@
 
 void JobQueue::PopForRun(int accepted_priority, std::vector<JobID>* jobs) {
   DCHECK_LT(accepted_priority, static_cast<int>(queue_.size()));
   jobs->clear();
 
   // Too many jobs are running already.
   if (running_.size() >= num_max_concurrent_jobs_)
     return;
 
   // Looks up the queue in the order of priority upto |accepted_priority|.
-  bool processing_batch_request = false;
-  int64 total_size = 0;
+  uint64 total_size = 0;
+  bool batchable = true;
   for (int priority = 0; priority <= accepted_priority; ++priority) {
-    auto it = queue_[priority].begin();
-    while (it != queue_[priority].end()) {
-      if (!processing_batch_request ||
-          (it->batchable && total_size + it->size <= max_batch_size_)) {
-        total_size += it->size;
-        processing_batch_request = it->batchable;
-        jobs->push_back(it->id);
-        running_.insert(it->id);
-        it = queue_[priority].erase(it);
-        if (processing_batch_request)
-          continue;
-      }
-      return;
+    while (!queue_[priority].empty()) {
+      const auto& item = queue_[priority].front();
+      total_size += item.size;
+      batchable = batchable && item.batchable && total_size <= max_batch_size_;
+      if (!(jobs->empty() || batchable))
+        return;
+      jobs->push_back(item.id);
+      running_.insert(item.id);
+      queue_[priority].pop_front();
     }
   }
 }
 
 void JobQueue::GetQueuedJobs(int priority, std::vector<JobID>* jobs) const {
   DCHECK_LT(priority, static_cast<int>(queue_.size()));
   jobs->clear();
   for (const Item& item : queue_[priority]) {
     jobs->push_back(item.id);
   }
@@ skipping 30 matching lines @@
     for (auto it = queue_[i].begin(); it != queue_[i].end(); ++it) {
       if (it->id == id) {
         queue_[i].erase(it);
         break;
       }
     }
   }
 }
 
 }  // namespace drive